2 #include <linux/sched.h>
3 #include <linux/sched/sysctl.h>
4 #include <linux/sched/rt.h>
5 #include <linux/sched/deadline.h>
6 #include <linux/mutex.h>
7 #include <linux/spinlock.h>
8 #include <linux/stop_machine.h>
9 #include <linux/tick.h>
10 #include <linux/slab.h>
13 #include "cpudeadline.h"
19 /* task_struct::on_rq states: */
20 #define TASK_ON_RQ_QUEUED 1
21 #define TASK_ON_RQ_MIGRATING 2
23 extern __read_mostly
int scheduler_running
;
25 extern unsigned long calc_load_update
;
26 extern atomic_long_t calc_load_tasks
;
28 extern long calc_load_fold_active(struct rq
*this_rq
);
29 extern void update_cpu_load_active(struct rq
*this_rq
);
32 * Helpers for converting nanosecond timing to jiffy resolution
34 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
37 * Increase resolution of nice-level calculations for 64-bit architectures.
38 * The extra resolution improves shares distribution and load balancing of
39 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
40 * hierarchies, especially on larger systems. This is not a user-visible change
41 * and does not change the user-interface for setting shares/weights.
43 * We increase resolution only if we have enough bits to allow this increased
44 * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
45 * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
48 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */
49 # define SCHED_LOAD_RESOLUTION 10
50 # define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION)
51 # define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION)
53 # define SCHED_LOAD_RESOLUTION 0
54 # define scale_load(w) (w)
55 # define scale_load_down(w) (w)
58 #define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION)
59 #define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT)
61 #define NICE_0_LOAD SCHED_LOAD_SCALE
62 #define NICE_0_SHIFT SCHED_LOAD_SHIFT
65 * Single value that decides SCHED_DEADLINE internal math precision.
66 * 10 -> just above 1us
67 * 9 -> just above 0.5us
72 * These are the 'tuning knobs' of the scheduler:
76 * single value that denotes runtime == period, ie unlimited time.
78 #define RUNTIME_INF ((u64)~0ULL)
80 static inline int fair_policy(int policy
)
82 return policy
== SCHED_NORMAL
|| policy
== SCHED_BATCH
;
85 static inline int rt_policy(int policy
)
87 return policy
== SCHED_FIFO
|| policy
== SCHED_RR
;
90 static inline int dl_policy(int policy
)
92 return policy
== SCHED_DEADLINE
;
95 static inline int task_has_rt_policy(struct task_struct
*p
)
97 return rt_policy(p
->policy
);
100 static inline int task_has_dl_policy(struct task_struct
*p
)
102 return dl_policy(p
->policy
);
105 static inline bool dl_time_before(u64 a
, u64 b
)
107 return (s64
)(a
- b
) < 0;
111 * Tells if entity @a should preempt entity @b.
114 dl_entity_preempt(struct sched_dl_entity
*a
, struct sched_dl_entity
*b
)
116 return dl_time_before(a
->deadline
, b
->deadline
);
120 * This is the priority-queue data structure of the RT scheduling class:
122 struct rt_prio_array
{
123 DECLARE_BITMAP(bitmap
, MAX_RT_PRIO
+1); /* include 1 bit for delimiter */
124 struct list_head queue
[MAX_RT_PRIO
];
127 struct rt_bandwidth
{
128 /* nests inside the rq lock: */
129 raw_spinlock_t rt_runtime_lock
;
132 struct hrtimer rt_period_timer
;
135 void __dl_clear_params(struct task_struct
*p
);
138 * To keep the bandwidth of -deadline tasks and groups under control
139 * we need some place where:
140 * - store the maximum -deadline bandwidth of the system (the group);
141 * - cache the fraction of that bandwidth that is currently allocated.
143 * This is all done in the data structure below. It is similar to the
144 * one used for RT-throttling (rt_bandwidth), with the main difference
145 * that, since here we are only interested in admission control, we
146 * do not decrease any runtime while the group "executes", neither we
147 * need a timer to replenish it.
149 * With respect to SMP, the bandwidth is given on a per-CPU basis,
151 * - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU;
152 * - dl_total_bw array contains, in the i-eth element, the currently
153 * allocated bandwidth on the i-eth CPU.
154 * Moreover, groups consume bandwidth on each CPU, while tasks only
155 * consume bandwidth on the CPU they're running on.
156 * Finally, dl_total_bw_cpu is used to cache the index of dl_total_bw
157 * that will be shown the next time the proc or cgroup controls will
158 * be red. It on its turn can be changed by writing on its own
161 struct dl_bandwidth
{
162 raw_spinlock_t dl_runtime_lock
;
167 static inline int dl_bandwidth_enabled(void)
169 return sysctl_sched_rt_runtime
>= 0;
172 extern struct dl_bw
*dl_bw_of(int i
);
180 void __dl_clear(struct dl_bw
*dl_b
, u64 tsk_bw
)
182 dl_b
->total_bw
-= tsk_bw
;
186 void __dl_add(struct dl_bw
*dl_b
, u64 tsk_bw
)
188 dl_b
->total_bw
+= tsk_bw
;
192 bool __dl_overflow(struct dl_bw
*dl_b
, int cpus
, u64 old_bw
, u64 new_bw
)
194 return dl_b
->bw
!= -1 &&
195 dl_b
->bw
* cpus
< dl_b
->total_bw
- old_bw
+ new_bw
;
198 extern struct mutex sched_domains_mutex
;
200 #ifdef CONFIG_CGROUP_SCHED
202 #include <linux/cgroup.h>
207 extern struct list_head task_groups
;
209 struct cfs_bandwidth
{
210 #ifdef CONFIG_CFS_BANDWIDTH
214 s64 hierarchical_quota
;
217 int idle
, timer_active
;
218 struct hrtimer period_timer
, slack_timer
;
219 struct list_head throttled_cfs_rq
;
222 int nr_periods
, nr_throttled
;
227 /* task group related information */
229 struct cgroup_subsys_state css
;
231 #ifdef CONFIG_FAIR_GROUP_SCHED
232 /* schedulable entities of this group on each cpu */
233 struct sched_entity
**se
;
234 /* runqueue "owned" by this group on each cpu */
235 struct cfs_rq
**cfs_rq
;
236 unsigned long shares
;
239 atomic_long_t load_avg
;
240 atomic_t runnable_avg
;
244 #ifdef CONFIG_RT_GROUP_SCHED
245 struct sched_rt_entity
**rt_se
;
246 struct rt_rq
**rt_rq
;
248 struct rt_bandwidth rt_bandwidth
;
252 struct list_head list
;
254 struct task_group
*parent
;
255 struct list_head siblings
;
256 struct list_head children
;
258 #ifdef CONFIG_SCHED_AUTOGROUP
259 struct autogroup
*autogroup
;
262 struct cfs_bandwidth cfs_bandwidth
;
265 #ifdef CONFIG_FAIR_GROUP_SCHED
266 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
269 * A weight of 0 or 1 can cause arithmetics problems.
270 * A weight of a cfs_rq is the sum of weights of which entities
271 * are queued on this cfs_rq, so a weight of a entity should not be
272 * too large, so as the shares value of a task group.
273 * (The default weight is 1024 - so there's no practical
274 * limitation from this.)
276 #define MIN_SHARES (1UL << 1)
277 #define MAX_SHARES (1UL << 18)
280 typedef int (*tg_visitor
)(struct task_group
*, void *);
282 extern int walk_tg_tree_from(struct task_group
*from
,
283 tg_visitor down
, tg_visitor up
, void *data
);
286 * Iterate the full tree, calling @down when first entering a node and @up when
287 * leaving it for the final time.
289 * Caller must hold rcu_lock or sufficient equivalent.
291 static inline int walk_tg_tree(tg_visitor down
, tg_visitor up
, void *data
)
293 return walk_tg_tree_from(&root_task_group
, down
, up
, data
);
296 extern int tg_nop(struct task_group
*tg
, void *data
);
298 extern void free_fair_sched_group(struct task_group
*tg
);
299 extern int alloc_fair_sched_group(struct task_group
*tg
, struct task_group
*parent
);
300 extern void unregister_fair_sched_group(struct task_group
*tg
, int cpu
);
301 extern void init_tg_cfs_entry(struct task_group
*tg
, struct cfs_rq
*cfs_rq
,
302 struct sched_entity
*se
, int cpu
,
303 struct sched_entity
*parent
);
304 extern void init_cfs_bandwidth(struct cfs_bandwidth
*cfs_b
);
305 extern int sched_group_set_shares(struct task_group
*tg
, unsigned long shares
);
307 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth
*cfs_b
);
308 extern void __start_cfs_bandwidth(struct cfs_bandwidth
*cfs_b
, bool force
);
309 extern void unthrottle_cfs_rq(struct cfs_rq
*cfs_rq
);
311 extern void free_rt_sched_group(struct task_group
*tg
);
312 extern int alloc_rt_sched_group(struct task_group
*tg
, struct task_group
*parent
);
313 extern void init_tg_rt_entry(struct task_group
*tg
, struct rt_rq
*rt_rq
,
314 struct sched_rt_entity
*rt_se
, int cpu
,
315 struct sched_rt_entity
*parent
);
317 extern struct task_group
*sched_create_group(struct task_group
*parent
);
318 extern void sched_online_group(struct task_group
*tg
,
319 struct task_group
*parent
);
320 extern void sched_destroy_group(struct task_group
*tg
);
321 extern void sched_offline_group(struct task_group
*tg
);
323 extern void sched_move_task(struct task_struct
*tsk
);
325 #ifdef CONFIG_FAIR_GROUP_SCHED
326 extern int sched_group_set_shares(struct task_group
*tg
, unsigned long shares
);
329 #else /* CONFIG_CGROUP_SCHED */
331 struct cfs_bandwidth
{ };
333 #endif /* CONFIG_CGROUP_SCHED */
335 /* CFS-related fields in a runqueue */
337 struct load_weight load
;
338 unsigned int nr_running
, h_nr_running
;
343 u64 min_vruntime_copy
;
346 struct rb_root tasks_timeline
;
347 struct rb_node
*rb_leftmost
;
350 * 'curr' points to currently running entity on this cfs_rq.
351 * It is set to NULL otherwise (i.e when none are currently running).
353 struct sched_entity
*curr
, *next
, *last
, *skip
;
355 #ifdef CONFIG_SCHED_DEBUG
356 unsigned int nr_spread_over
;
362 * Under CFS, load is tracked on a per-entity basis and aggregated up.
363 * This allows for the description of both thread and group usage (in
364 * the FAIR_GROUP_SCHED case).
366 unsigned long runnable_load_avg
, blocked_load_avg
;
367 atomic64_t decay_counter
;
369 atomic_long_t removed_load
;
371 #ifdef CONFIG_FAIR_GROUP_SCHED
372 /* Required to track per-cpu representation of a task_group */
373 u32 tg_runnable_contrib
;
374 unsigned long tg_load_contrib
;
377 * h_load = weight * f(tg)
379 * Where f(tg) is the recursive weight fraction assigned to
382 unsigned long h_load
;
383 u64 last_h_load_update
;
384 struct sched_entity
*h_load_next
;
385 #endif /* CONFIG_FAIR_GROUP_SCHED */
386 #endif /* CONFIG_SMP */
388 #ifdef CONFIG_FAIR_GROUP_SCHED
389 struct rq
*rq
; /* cpu runqueue to which this cfs_rq is attached */
392 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
393 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
394 * (like users, containers etc.)
396 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
397 * list is used during load balance.
400 struct list_head leaf_cfs_rq_list
;
401 struct task_group
*tg
; /* group that "owns" this runqueue */
403 #ifdef CONFIG_CFS_BANDWIDTH
406 s64 runtime_remaining
;
408 u64 throttled_clock
, throttled_clock_task
;
409 u64 throttled_clock_task_time
;
410 int throttled
, throttle_count
;
411 struct list_head throttled_list
;
412 #endif /* CONFIG_CFS_BANDWIDTH */
413 #endif /* CONFIG_FAIR_GROUP_SCHED */
416 static inline int rt_bandwidth_enabled(void)
418 return sysctl_sched_rt_runtime
>= 0;
421 /* Real-Time classes' related field in a runqueue: */
423 struct rt_prio_array active
;
424 unsigned int rt_nr_running
;
425 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
427 int curr
; /* highest queued rt task prio */
429 int next
; /* next highest */
434 unsigned long rt_nr_migratory
;
435 unsigned long rt_nr_total
;
437 struct plist_head pushable_tasks
;
444 /* Nests inside the rq lock: */
445 raw_spinlock_t rt_runtime_lock
;
447 #ifdef CONFIG_RT_GROUP_SCHED
448 unsigned long rt_nr_boosted
;
451 struct task_group
*tg
;
455 /* Deadline class' related fields in a runqueue */
457 /* runqueue is an rbtree, ordered by deadline */
458 struct rb_root rb_root
;
459 struct rb_node
*rb_leftmost
;
461 unsigned long dl_nr_running
;
465 * Deadline values of the currently executing and the
466 * earliest ready task on this rq. Caching these facilitates
467 * the decision wether or not a ready but not running task
468 * should migrate somewhere else.
475 unsigned long dl_nr_migratory
;
479 * Tasks on this rq that can be pushed away. They are kept in
480 * an rb-tree, ordered by tasks' deadlines, with caching
481 * of the leftmost (earliest deadline) element.
483 struct rb_root pushable_dl_tasks_root
;
484 struct rb_node
*pushable_dl_tasks_leftmost
;
493 * We add the notion of a root-domain which will be used to define per-domain
494 * variables. Each exclusive cpuset essentially defines an island domain by
495 * fully partitioning the member cpus from any other cpuset. Whenever a new
496 * exclusive cpuset is created, we also create and attach a new root-domain
505 cpumask_var_t online
;
507 /* Indicate more than one runnable task for any CPU */
511 * The bit corresponding to a CPU gets set here if such CPU has more
512 * than one runnable -deadline task (as it is below for RT tasks).
514 cpumask_var_t dlo_mask
;
520 * The "RT overload" flag: it gets set if a CPU has more than
521 * one runnable RT task.
523 cpumask_var_t rto_mask
;
524 struct cpupri cpupri
;
527 extern struct root_domain def_root_domain
;
529 #endif /* CONFIG_SMP */
532 * This is the main, per-CPU runqueue data structure.
534 * Locking rule: those places that want to lock multiple runqueues
535 * (such as the load balancing or the thread migration code), lock
536 * acquire operations must be ordered by ascending &runqueue.
543 * nr_running and cpu_load should be in the same cacheline because
544 * remote CPUs use both these fields when doing load calculation.
546 unsigned int nr_running
;
547 #ifdef CONFIG_NUMA_BALANCING
548 unsigned int nr_numa_running
;
549 unsigned int nr_preferred_running
;
551 #define CPU_LOAD_IDX_MAX 5
552 unsigned long cpu_load
[CPU_LOAD_IDX_MAX
];
553 unsigned long last_load_update_tick
;
554 #ifdef CONFIG_NO_HZ_COMMON
556 unsigned long nohz_flags
;
558 #ifdef CONFIG_NO_HZ_FULL
559 unsigned long last_sched_tick
;
561 int skip_clock_update
;
563 /* capture load from *all* tasks on this cpu: */
564 struct load_weight load
;
565 unsigned long nr_load_updates
;
572 #ifdef CONFIG_FAIR_GROUP_SCHED
573 /* list of leaf cfs_rq on this cpu: */
574 struct list_head leaf_cfs_rq_list
;
576 struct sched_avg avg
;
577 #endif /* CONFIG_FAIR_GROUP_SCHED */
580 * This is part of a global counter where only the total sum
581 * over all CPUs matters. A task can increase this counter on
582 * one CPU and if it got migrated afterwards it may decrease
583 * it on another CPU. Always updated under the runqueue lock:
585 unsigned long nr_uninterruptible
;
587 struct task_struct
*curr
, *idle
, *stop
;
588 unsigned long next_balance
;
589 struct mm_struct
*prev_mm
;
597 struct root_domain
*rd
;
598 struct sched_domain
*sd
;
600 unsigned long cpu_capacity
;
602 unsigned char idle_balance
;
603 /* For active balancing */
607 struct cpu_stop_work active_balance_work
;
608 /* cpu of this runqueue: */
612 struct list_head cfs_tasks
;
619 /* This is used to determine avg_idle's max value */
620 u64 max_idle_balance_cost
;
623 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
626 #ifdef CONFIG_PARAVIRT
629 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
630 u64 prev_steal_time_rq
;
633 /* calc_load related fields */
634 unsigned long calc_load_update
;
635 long calc_load_active
;
637 #ifdef CONFIG_SCHED_HRTICK
639 int hrtick_csd_pending
;
640 struct call_single_data hrtick_csd
;
642 struct hrtimer hrtick_timer
;
645 #ifdef CONFIG_SCHEDSTATS
647 struct sched_info rq_sched_info
;
648 unsigned long long rq_cpu_time
;
649 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
651 /* sys_sched_yield() stats */
652 unsigned int yld_count
;
654 /* schedule() stats */
655 unsigned int sched_count
;
656 unsigned int sched_goidle
;
658 /* try_to_wake_up() stats */
659 unsigned int ttwu_count
;
660 unsigned int ttwu_local
;
664 struct llist_head wake_list
;
667 #ifdef CONFIG_CPU_IDLE
668 /* Must be inspected within a rcu lock section */
669 struct cpuidle_state
*idle_state
;
673 static inline int cpu_of(struct rq
*rq
)
682 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq
, runqueues
);
684 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
685 #define this_rq() this_cpu_ptr(&runqueues)
686 #define task_rq(p) cpu_rq(task_cpu(p))
687 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
688 #define raw_rq() raw_cpu_ptr(&runqueues)
690 static inline u64
rq_clock(struct rq
*rq
)
695 static inline u64
rq_clock_task(struct rq
*rq
)
697 return rq
->clock_task
;
701 enum numa_topology_type
{
706 extern enum numa_topology_type sched_numa_topology_type
;
707 extern int sched_max_numa_distance
;
708 extern bool find_numa_distance(int distance
);
711 #ifdef CONFIG_NUMA_BALANCING
712 /* The regions in numa_faults array from task_struct */
713 enum numa_faults_stats
{
719 extern void sched_setnuma(struct task_struct
*p
, int node
);
720 extern int migrate_task_to(struct task_struct
*p
, int cpu
);
721 extern int migrate_swap(struct task_struct
*, struct task_struct
*);
722 #endif /* CONFIG_NUMA_BALANCING */
726 extern void sched_ttwu_pending(void);
728 #define rcu_dereference_check_sched_domain(p) \
729 rcu_dereference_check((p), \
730 lockdep_is_held(&sched_domains_mutex))
733 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
734 * See detach_destroy_domains: synchronize_sched for details.
736 * The domain tree of any CPU may only be accessed from within
737 * preempt-disabled sections.
739 #define for_each_domain(cpu, __sd) \
740 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
741 __sd; __sd = __sd->parent)
743 #define for_each_lower_domain(sd) for (; sd; sd = sd->child)
746 * highest_flag_domain - Return highest sched_domain containing flag.
747 * @cpu: The cpu whose highest level of sched domain is to
749 * @flag: The flag to check for the highest sched_domain
752 * Returns the highest sched_domain of a cpu which contains the given flag.
754 static inline struct sched_domain
*highest_flag_domain(int cpu
, int flag
)
756 struct sched_domain
*sd
, *hsd
= NULL
;
758 for_each_domain(cpu
, sd
) {
759 if (!(sd
->flags
& flag
))
767 static inline struct sched_domain
*lowest_flag_domain(int cpu
, int flag
)
769 struct sched_domain
*sd
;
771 for_each_domain(cpu
, sd
) {
772 if (sd
->flags
& flag
)
779 DECLARE_PER_CPU(struct sched_domain
*, sd_llc
);
780 DECLARE_PER_CPU(int, sd_llc_size
);
781 DECLARE_PER_CPU(int, sd_llc_id
);
782 DECLARE_PER_CPU(struct sched_domain
*, sd_numa
);
783 DECLARE_PER_CPU(struct sched_domain
*, sd_busy
);
784 DECLARE_PER_CPU(struct sched_domain
*, sd_asym
);
786 struct sched_group_capacity
{
789 * CPU capacity of this group, SCHED_LOAD_SCALE being max capacity
792 unsigned int capacity
, capacity_orig
;
793 unsigned long next_update
;
794 int imbalance
; /* XXX unrelated to capacity but shared group state */
796 * Number of busy cpus in this group.
798 atomic_t nr_busy_cpus
;
800 unsigned long cpumask
[0]; /* iteration mask */
804 struct sched_group
*next
; /* Must be a circular list */
807 unsigned int group_weight
;
808 struct sched_group_capacity
*sgc
;
811 * The CPUs this group covers.
813 * NOTE: this field is variable length. (Allocated dynamically
814 * by attaching extra space to the end of the structure,
815 * depending on how many CPUs the kernel has booted up with)
817 unsigned long cpumask
[0];
820 static inline struct cpumask
*sched_group_cpus(struct sched_group
*sg
)
822 return to_cpumask(sg
->cpumask
);
826 * cpumask masking which cpus in the group are allowed to iterate up the domain
829 static inline struct cpumask
*sched_group_mask(struct sched_group
*sg
)
831 return to_cpumask(sg
->sgc
->cpumask
);
835 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
836 * @group: The group whose first cpu is to be returned.
838 static inline unsigned int group_first_cpu(struct sched_group
*group
)
840 return cpumask_first(sched_group_cpus(group
));
843 extern int group_balance_cpu(struct sched_group
*sg
);
847 static inline void sched_ttwu_pending(void) { }
849 #endif /* CONFIG_SMP */
852 #include "auto_group.h"
854 #ifdef CONFIG_CGROUP_SCHED
857 * Return the group to which this tasks belongs.
859 * We cannot use task_css() and friends because the cgroup subsystem
860 * changes that value before the cgroup_subsys::attach() method is called,
861 * therefore we cannot pin it and might observe the wrong value.
863 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
864 * core changes this before calling sched_move_task().
866 * Instead we use a 'copy' which is updated from sched_move_task() while
867 * holding both task_struct::pi_lock and rq::lock.
869 static inline struct task_group
*task_group(struct task_struct
*p
)
871 return p
->sched_task_group
;
874 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
875 static inline void set_task_rq(struct task_struct
*p
, unsigned int cpu
)
877 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
878 struct task_group
*tg
= task_group(p
);
881 #ifdef CONFIG_FAIR_GROUP_SCHED
882 p
->se
.cfs_rq
= tg
->cfs_rq
[cpu
];
883 p
->se
.parent
= tg
->se
[cpu
];
886 #ifdef CONFIG_RT_GROUP_SCHED
887 p
->rt
.rt_rq
= tg
->rt_rq
[cpu
];
888 p
->rt
.parent
= tg
->rt_se
[cpu
];
892 #else /* CONFIG_CGROUP_SCHED */
894 static inline void set_task_rq(struct task_struct
*p
, unsigned int cpu
) { }
895 static inline struct task_group
*task_group(struct task_struct
*p
)
900 #endif /* CONFIG_CGROUP_SCHED */
902 static inline void __set_task_cpu(struct task_struct
*p
, unsigned int cpu
)
907 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
908 * successfuly executed on another CPU. We must ensure that updates of
909 * per-task data have been completed by this moment.
912 task_thread_info(p
)->cpu
= cpu
;
918 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
920 #ifdef CONFIG_SCHED_DEBUG
921 # include <linux/static_key.h>
922 # define const_debug __read_mostly
924 # define const_debug const
927 extern const_debug
unsigned int sysctl_sched_features
;
929 #define SCHED_FEAT(name, enabled) \
930 __SCHED_FEAT_##name ,
933 #include "features.h"
939 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
940 #define SCHED_FEAT(name, enabled) \
941 static __always_inline bool static_branch_##name(struct static_key *key) \
943 return static_key_##enabled(key); \
946 #include "features.h"
950 extern struct static_key sched_feat_keys
[__SCHED_FEAT_NR
];
951 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
952 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
953 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
954 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
956 #ifdef CONFIG_NUMA_BALANCING
957 #define sched_feat_numa(x) sched_feat(x)
958 #ifdef CONFIG_SCHED_DEBUG
959 #define numabalancing_enabled sched_feat_numa(NUMA)
961 extern bool numabalancing_enabled
;
962 #endif /* CONFIG_SCHED_DEBUG */
964 #define sched_feat_numa(x) (0)
965 #define numabalancing_enabled (0)
966 #endif /* CONFIG_NUMA_BALANCING */
968 static inline u64
global_rt_period(void)
970 return (u64
)sysctl_sched_rt_period
* NSEC_PER_USEC
;
973 static inline u64
global_rt_runtime(void)
975 if (sysctl_sched_rt_runtime
< 0)
978 return (u64
)sysctl_sched_rt_runtime
* NSEC_PER_USEC
;
981 static inline int task_current(struct rq
*rq
, struct task_struct
*p
)
983 return rq
->curr
== p
;
986 static inline int task_running(struct rq
*rq
, struct task_struct
*p
)
991 return task_current(rq
, p
);
995 static inline int task_on_rq_queued(struct task_struct
*p
)
997 return p
->on_rq
== TASK_ON_RQ_QUEUED
;
1000 static inline int task_on_rq_migrating(struct task_struct
*p
)
1002 return p
->on_rq
== TASK_ON_RQ_MIGRATING
;
1005 #ifndef prepare_arch_switch
1006 # define prepare_arch_switch(next) do { } while (0)
1008 #ifndef finish_arch_switch
1009 # define finish_arch_switch(prev) do { } while (0)
1011 #ifndef finish_arch_post_lock_switch
1012 # define finish_arch_post_lock_switch() do { } while (0)
1015 static inline void prepare_lock_switch(struct rq
*rq
, struct task_struct
*next
)
1019 * We can optimise this out completely for !SMP, because the
1020 * SMP rebalancing from interrupt is the only thing that cares
1027 static inline void finish_lock_switch(struct rq
*rq
, struct task_struct
*prev
)
1031 * After ->on_cpu is cleared, the task can be moved to a different CPU.
1032 * We must ensure this doesn't happen until the switch is completely
1038 #ifdef CONFIG_DEBUG_SPINLOCK
1039 /* this is a valid case when another task releases the spinlock */
1040 rq
->lock
.owner
= current
;
1043 * If we are tracking spinlock dependencies then we have to
1044 * fix up the runqueue lock - which gets 'carried over' from
1045 * prev into current:
1047 spin_acquire(&rq
->lock
.dep_map
, 0, 0, _THIS_IP_
);
1049 raw_spin_unlock_irq(&rq
->lock
);
1055 #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */
1056 #define WF_FORK 0x02 /* child wakeup after fork */
1057 #define WF_MIGRATED 0x4 /* internal use, task got migrated */
1060 * To aid in avoiding the subversion of "niceness" due to uneven distribution
1061 * of tasks with abnormal "nice" values across CPUs the contribution that
1062 * each task makes to its run queue's load is weighted according to its
1063 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
1064 * scaled version of the new time slice allocation that they receive on time
1068 #define WEIGHT_IDLEPRIO 3
1069 #define WMULT_IDLEPRIO 1431655765
1072 * Nice levels are multiplicative, with a gentle 10% change for every
1073 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to
1074 * nice 1, it will get ~10% less CPU time than another CPU-bound task
1075 * that remained on nice 0.
1077 * The "10% effect" is relative and cumulative: from _any_ nice level,
1078 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level
1079 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
1080 * If a task goes up by ~10% and another task goes down by ~10% then
1081 * the relative distance between them is ~25%.)
1083 static const int prio_to_weight
[40] = {
1084 /* -20 */ 88761, 71755, 56483, 46273, 36291,
1085 /* -15 */ 29154, 23254, 18705, 14949, 11916,
1086 /* -10 */ 9548, 7620, 6100, 4904, 3906,
1087 /* -5 */ 3121, 2501, 1991, 1586, 1277,
1088 /* 0 */ 1024, 820, 655, 526, 423,
1089 /* 5 */ 335, 272, 215, 172, 137,
1090 /* 10 */ 110, 87, 70, 56, 45,
1091 /* 15 */ 36, 29, 23, 18, 15,
1095 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated.
1097 * In cases where the weight does not change often, we can use the
1098 * precalculated inverse to speed up arithmetics by turning divisions
1099 * into multiplications:
1101 static const u32 prio_to_wmult
[40] = {
1102 /* -20 */ 48388, 59856, 76040, 92818, 118348,
1103 /* -15 */ 147320, 184698, 229616, 287308, 360437,
1104 /* -10 */ 449829, 563644, 704093, 875809, 1099582,
1105 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326,
1106 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587,
1107 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126,
1108 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717,
1109 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
1112 #define ENQUEUE_WAKEUP 1
1113 #define ENQUEUE_HEAD 2
1115 #define ENQUEUE_WAKING 4 /* sched_class::task_waking was called */
1117 #define ENQUEUE_WAKING 0
1119 #define ENQUEUE_REPLENISH 8
1121 #define DEQUEUE_SLEEP 1
1123 #define RETRY_TASK ((void *)-1UL)
1125 struct sched_class
{
1126 const struct sched_class
*next
;
1128 void (*enqueue_task
) (struct rq
*rq
, struct task_struct
*p
, int flags
);
1129 void (*dequeue_task
) (struct rq
*rq
, struct task_struct
*p
, int flags
);
1130 void (*yield_task
) (struct rq
*rq
);
1131 bool (*yield_to_task
) (struct rq
*rq
, struct task_struct
*p
, bool preempt
);
1133 void (*check_preempt_curr
) (struct rq
*rq
, struct task_struct
*p
, int flags
);
1136 * It is the responsibility of the pick_next_task() method that will
1137 * return the next task to call put_prev_task() on the @prev task or
1138 * something equivalent.
1140 * May return RETRY_TASK when it finds a higher prio class has runnable
1143 struct task_struct
* (*pick_next_task
) (struct rq
*rq
,
1144 struct task_struct
*prev
);
1145 void (*put_prev_task
) (struct rq
*rq
, struct task_struct
*p
);
1148 int (*select_task_rq
)(struct task_struct
*p
, int task_cpu
, int sd_flag
, int flags
);
1149 void (*migrate_task_rq
)(struct task_struct
*p
, int next_cpu
);
1151 void (*post_schedule
) (struct rq
*this_rq
);
1152 void (*task_waking
) (struct task_struct
*task
);
1153 void (*task_woken
) (struct rq
*this_rq
, struct task_struct
*task
);
1155 void (*set_cpus_allowed
)(struct task_struct
*p
,
1156 const struct cpumask
*newmask
);
1158 void (*rq_online
)(struct rq
*rq
);
1159 void (*rq_offline
)(struct rq
*rq
);
1162 void (*set_curr_task
) (struct rq
*rq
);
1163 void (*task_tick
) (struct rq
*rq
, struct task_struct
*p
, int queued
);
1164 void (*task_fork
) (struct task_struct
*p
);
1165 void (*task_dead
) (struct task_struct
*p
);
1168 * The switched_from() call is allowed to drop rq->lock, therefore we
1169 * cannot assume the switched_from/switched_to pair is serliazed by
1170 * rq->lock. They are however serialized by p->pi_lock.
1172 void (*switched_from
) (struct rq
*this_rq
, struct task_struct
*task
);
1173 void (*switched_to
) (struct rq
*this_rq
, struct task_struct
*task
);
1174 void (*prio_changed
) (struct rq
*this_rq
, struct task_struct
*task
,
1177 unsigned int (*get_rr_interval
) (struct rq
*rq
,
1178 struct task_struct
*task
);
1180 void (*update_curr
) (struct rq
*rq
);
1182 #ifdef CONFIG_FAIR_GROUP_SCHED
1183 void (*task_move_group
) (struct task_struct
*p
, int on_rq
);
1187 static inline void put_prev_task(struct rq
*rq
, struct task_struct
*prev
)
1189 prev
->sched_class
->put_prev_task(rq
, prev
);
1192 #define sched_class_highest (&stop_sched_class)
1193 #define for_each_class(class) \
1194 for (class = sched_class_highest; class; class = class->next)
1196 extern const struct sched_class stop_sched_class
;
1197 extern const struct sched_class dl_sched_class
;
1198 extern const struct sched_class rt_sched_class
;
1199 extern const struct sched_class fair_sched_class
;
1200 extern const struct sched_class idle_sched_class
;
1205 extern void update_group_capacity(struct sched_domain
*sd
, int cpu
);
1207 extern void trigger_load_balance(struct rq
*rq
);
1209 extern void idle_enter_fair(struct rq
*this_rq
);
1210 extern void idle_exit_fair(struct rq
*this_rq
);
1214 static inline void idle_enter_fair(struct rq
*rq
) { }
1215 static inline void idle_exit_fair(struct rq
*rq
) { }
1219 #ifdef CONFIG_CPU_IDLE
1220 static inline void idle_set_state(struct rq
*rq
,
1221 struct cpuidle_state
*idle_state
)
1223 rq
->idle_state
= idle_state
;
1226 static inline struct cpuidle_state
*idle_get_state(struct rq
*rq
)
1228 WARN_ON(!rcu_read_lock_held());
1229 return rq
->idle_state
;
1232 static inline void idle_set_state(struct rq
*rq
,
1233 struct cpuidle_state
*idle_state
)
1237 static inline struct cpuidle_state
*idle_get_state(struct rq
*rq
)
1243 extern void sysrq_sched_debug_show(void);
1244 extern void sched_init_granularity(void);
1245 extern void update_max_interval(void);
1247 extern void init_sched_dl_class(void);
1248 extern void init_sched_rt_class(void);
1249 extern void init_sched_fair_class(void);
1250 extern void init_sched_dl_class(void);
1252 extern void resched_curr(struct rq
*rq
);
1253 extern void resched_cpu(int cpu
);
1255 extern struct rt_bandwidth def_rt_bandwidth
;
1256 extern void init_rt_bandwidth(struct rt_bandwidth
*rt_b
, u64 period
, u64 runtime
);
1258 extern struct dl_bandwidth def_dl_bandwidth
;
1259 extern void init_dl_bandwidth(struct dl_bandwidth
*dl_b
, u64 period
, u64 runtime
);
1260 extern void init_dl_task_timer(struct sched_dl_entity
*dl_se
);
1262 unsigned long to_ratio(u64 period
, u64 runtime
);
1264 extern void update_idle_cpu_load(struct rq
*this_rq
);
1266 extern void init_task_runnable_average(struct task_struct
*p
);
1268 static inline void add_nr_running(struct rq
*rq
, unsigned count
)
1270 unsigned prev_nr
= rq
->nr_running
;
1272 rq
->nr_running
= prev_nr
+ count
;
1274 if (prev_nr
< 2 && rq
->nr_running
>= 2) {
1276 if (!rq
->rd
->overload
)
1277 rq
->rd
->overload
= true;
1280 #ifdef CONFIG_NO_HZ_FULL
1281 if (tick_nohz_full_cpu(rq
->cpu
)) {
1283 * Tick is needed if more than one task runs on a CPU.
1284 * Send the target an IPI to kick it out of nohz mode.
1286 * We assume that IPI implies full memory barrier and the
1287 * new value of rq->nr_running is visible on reception
1290 tick_nohz_full_kick_cpu(rq
->cpu
);
1296 static inline void sub_nr_running(struct rq
*rq
, unsigned count
)
1298 rq
->nr_running
-= count
;
1301 static inline void rq_last_tick_reset(struct rq
*rq
)
1303 #ifdef CONFIG_NO_HZ_FULL
1304 rq
->last_sched_tick
= jiffies
;
1308 extern void update_rq_clock(struct rq
*rq
);
1310 extern void activate_task(struct rq
*rq
, struct task_struct
*p
, int flags
);
1311 extern void deactivate_task(struct rq
*rq
, struct task_struct
*p
, int flags
);
1313 extern void check_preempt_curr(struct rq
*rq
, struct task_struct
*p
, int flags
);
1315 extern const_debug
unsigned int sysctl_sched_time_avg
;
1316 extern const_debug
unsigned int sysctl_sched_nr_migrate
;
1317 extern const_debug
unsigned int sysctl_sched_migration_cost
;
1319 static inline u64
sched_avg_period(void)
1321 return (u64
)sysctl_sched_time_avg
* NSEC_PER_MSEC
/ 2;
1324 #ifdef CONFIG_SCHED_HRTICK
1328 * - enabled by features
1329 * - hrtimer is actually high res
1331 static inline int hrtick_enabled(struct rq
*rq
)
1333 if (!sched_feat(HRTICK
))
1335 if (!cpu_active(cpu_of(rq
)))
1337 return hrtimer_is_hres_active(&rq
->hrtick_timer
);
1340 void hrtick_start(struct rq
*rq
, u64 delay
);
1344 static inline int hrtick_enabled(struct rq
*rq
)
1349 #endif /* CONFIG_SCHED_HRTICK */
1352 extern void sched_avg_update(struct rq
*rq
);
1353 static inline void sched_rt_avg_update(struct rq
*rq
, u64 rt_delta
)
1355 rq
->rt_avg
+= rt_delta
;
1356 sched_avg_update(rq
);
1359 static inline void sched_rt_avg_update(struct rq
*rq
, u64 rt_delta
) { }
1360 static inline void sched_avg_update(struct rq
*rq
) { }
1363 extern void start_bandwidth_timer(struct hrtimer
*period_timer
, ktime_t period
);
1366 #ifdef CONFIG_PREEMPT
1368 static inline void double_rq_lock(struct rq
*rq1
, struct rq
*rq2
);
1371 * fair double_lock_balance: Safely acquires both rq->locks in a fair
1372 * way at the expense of forcing extra atomic operations in all
1373 * invocations. This assures that the double_lock is acquired using the
1374 * same underlying policy as the spinlock_t on this architecture, which
1375 * reduces latency compared to the unfair variant below. However, it
1376 * also adds more overhead and therefore may reduce throughput.
1378 static inline int _double_lock_balance(struct rq
*this_rq
, struct rq
*busiest
)
1379 __releases(this_rq
->lock
)
1380 __acquires(busiest
->lock
)
1381 __acquires(this_rq
->lock
)
1383 raw_spin_unlock(&this_rq
->lock
);
1384 double_rq_lock(this_rq
, busiest
);
1391 * Unfair double_lock_balance: Optimizes throughput at the expense of
1392 * latency by eliminating extra atomic operations when the locks are
1393 * already in proper order on entry. This favors lower cpu-ids and will
1394 * grant the double lock to lower cpus over higher ids under contention,
1395 * regardless of entry order into the function.
1397 static inline int _double_lock_balance(struct rq
*this_rq
, struct rq
*busiest
)
1398 __releases(this_rq
->lock
)
1399 __acquires(busiest
->lock
)
1400 __acquires(this_rq
->lock
)
1404 if (unlikely(!raw_spin_trylock(&busiest
->lock
))) {
1405 if (busiest
< this_rq
) {
1406 raw_spin_unlock(&this_rq
->lock
);
1407 raw_spin_lock(&busiest
->lock
);
1408 raw_spin_lock_nested(&this_rq
->lock
,
1409 SINGLE_DEPTH_NESTING
);
1412 raw_spin_lock_nested(&busiest
->lock
,
1413 SINGLE_DEPTH_NESTING
);
1418 #endif /* CONFIG_PREEMPT */
1421 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
1423 static inline int double_lock_balance(struct rq
*this_rq
, struct rq
*busiest
)
1425 if (unlikely(!irqs_disabled())) {
1426 /* printk() doesn't work good under rq->lock */
1427 raw_spin_unlock(&this_rq
->lock
);
1431 return _double_lock_balance(this_rq
, busiest
);
1434 static inline void double_unlock_balance(struct rq
*this_rq
, struct rq
*busiest
)
1435 __releases(busiest
->lock
)
1437 raw_spin_unlock(&busiest
->lock
);
1438 lock_set_subclass(&this_rq
->lock
.dep_map
, 0, _RET_IP_
);
1441 static inline void double_lock(spinlock_t
*l1
, spinlock_t
*l2
)
1447 spin_lock_nested(l2
, SINGLE_DEPTH_NESTING
);
1450 static inline void double_lock_irq(spinlock_t
*l1
, spinlock_t
*l2
)
1456 spin_lock_nested(l2
, SINGLE_DEPTH_NESTING
);
1459 static inline void double_raw_lock(raw_spinlock_t
*l1
, raw_spinlock_t
*l2
)
1465 raw_spin_lock_nested(l2
, SINGLE_DEPTH_NESTING
);
1469 * double_rq_lock - safely lock two runqueues
1471 * Note this does not disable interrupts like task_rq_lock,
1472 * you need to do so manually before calling.
1474 static inline void double_rq_lock(struct rq
*rq1
, struct rq
*rq2
)
1475 __acquires(rq1
->lock
)
1476 __acquires(rq2
->lock
)
1478 BUG_ON(!irqs_disabled());
1480 raw_spin_lock(&rq1
->lock
);
1481 __acquire(rq2
->lock
); /* Fake it out ;) */
1484 raw_spin_lock(&rq1
->lock
);
1485 raw_spin_lock_nested(&rq2
->lock
, SINGLE_DEPTH_NESTING
);
1487 raw_spin_lock(&rq2
->lock
);
1488 raw_spin_lock_nested(&rq1
->lock
, SINGLE_DEPTH_NESTING
);
1494 * double_rq_unlock - safely unlock two runqueues
1496 * Note this does not restore interrupts like task_rq_unlock,
1497 * you need to do so manually after calling.
1499 static inline void double_rq_unlock(struct rq
*rq1
, struct rq
*rq2
)
1500 __releases(rq1
->lock
)
1501 __releases(rq2
->lock
)
1503 raw_spin_unlock(&rq1
->lock
);
1505 raw_spin_unlock(&rq2
->lock
);
1507 __release(rq2
->lock
);
1510 #else /* CONFIG_SMP */
1513 * double_rq_lock - safely lock two runqueues
1515 * Note this does not disable interrupts like task_rq_lock,
1516 * you need to do so manually before calling.
1518 static inline void double_rq_lock(struct rq
*rq1
, struct rq
*rq2
)
1519 __acquires(rq1
->lock
)
1520 __acquires(rq2
->lock
)
1522 BUG_ON(!irqs_disabled());
1524 raw_spin_lock(&rq1
->lock
);
1525 __acquire(rq2
->lock
); /* Fake it out ;) */
1529 * double_rq_unlock - safely unlock two runqueues
1531 * Note this does not restore interrupts like task_rq_unlock,
1532 * you need to do so manually after calling.
1534 static inline void double_rq_unlock(struct rq
*rq1
, struct rq
*rq2
)
1535 __releases(rq1
->lock
)
1536 __releases(rq2
->lock
)
1539 raw_spin_unlock(&rq1
->lock
);
1540 __release(rq2
->lock
);
1545 extern struct sched_entity
*__pick_first_entity(struct cfs_rq
*cfs_rq
);
1546 extern struct sched_entity
*__pick_last_entity(struct cfs_rq
*cfs_rq
);
1547 extern void print_cfs_stats(struct seq_file
*m
, int cpu
);
1548 extern void print_rt_stats(struct seq_file
*m
, int cpu
);
1549 extern void print_dl_stats(struct seq_file
*m
, int cpu
);
1551 extern void init_cfs_rq(struct cfs_rq
*cfs_rq
);
1552 extern void init_rt_rq(struct rt_rq
*rt_rq
, struct rq
*rq
);
1553 extern void init_dl_rq(struct dl_rq
*dl_rq
, struct rq
*rq
);
1555 extern void cfs_bandwidth_usage_inc(void);
1556 extern void cfs_bandwidth_usage_dec(void);
1558 #ifdef CONFIG_NO_HZ_COMMON
1559 enum rq_nohz_flag_bits
{
1564 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
1567 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1569 DECLARE_PER_CPU(u64
, cpu_hardirq_time
);
1570 DECLARE_PER_CPU(u64
, cpu_softirq_time
);
1572 #ifndef CONFIG_64BIT
1573 DECLARE_PER_CPU(seqcount_t
, irq_time_seq
);
1575 static inline void irq_time_write_begin(void)
1577 __this_cpu_inc(irq_time_seq
.sequence
);
1581 static inline void irq_time_write_end(void)
1584 __this_cpu_inc(irq_time_seq
.sequence
);
1587 static inline u64
irq_time_read(int cpu
)
1593 seq
= read_seqcount_begin(&per_cpu(irq_time_seq
, cpu
));
1594 irq_time
= per_cpu(cpu_softirq_time
, cpu
) +
1595 per_cpu(cpu_hardirq_time
, cpu
);
1596 } while (read_seqcount_retry(&per_cpu(irq_time_seq
, cpu
), seq
));
1600 #else /* CONFIG_64BIT */
1601 static inline void irq_time_write_begin(void)
1605 static inline void irq_time_write_end(void)
1609 static inline u64
irq_time_read(int cpu
)
1611 return per_cpu(cpu_softirq_time
, cpu
) + per_cpu(cpu_hardirq_time
, cpu
);
1613 #endif /* CONFIG_64BIT */
1614 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */